Pulling tool

ABSTRACT

A pulling tool for removal of a hub from a shaft including a pulling ring having a peripheral flange engageable by a conventional puller and an internal axial opening having tapered seat surface means for receiving and supporting a pair of jaws which have internal teeth for engaging the outer surface of the hub of the shaft. In one form of the device the axial opening comprises an internal tapered bore while in another form of the device, the opening is defined by a plurality of circumferentially spaced slots for receiving and supporting the jaws at different selected distances from the axis of the pulling ring to accommodate the device to different hub sizes. The tool permits the engagement of a hub and the application of sufficient pulling force to pull the hub from the shaft on which the hub is stuck by corrosion and the like.

United States Patent [191 Russell PULLING TOOL [76] Inventor: Curtis J. Russell, 9344 Haven Cove, Dallas, Tex. 75227 22 Filed: May21,1973

21 App1.No.:362,362

Related US. Application Data [63] Continuation-impart of Ser. No. 123,152, March 11,

1971, Pat. No. 3,748,718.

521 U.S.Cl. ..29/283,29/264 51 rm.c1 ..B23q3/0s 5s FieldofSearch ..29/258,259,260,2.61,

[56] References Cited UNITED STATES PATENTS 1,443,052 1/1923 Stephens 29/258 1,654,009 12/1927 Merten 29/264 1,780,888 11/1930 Uebelhoer 29/264 [4 1 Feb. 4, 1975 Primary ExaminerAl Lawrence Smith Assistant Examinerl-laro1d P. Smith, Jr. Attorney, Agent, or Firm-H. Mathews Garland [57] ABSTRACT A pulling tool for removal of a hub from a shaft including a pulling ring having a peripheral flange engageable by a conventional puller and an internal axial opening having tapered seat surface means for receiving and supporting a pair of jaws which have internal teeth for engaging the outer surface of the hub of the shaft. In one form of the device the axial opening comprises an internal tapered bore while in another form of the device, the opening is defined by a plurality of circumferentially spaced slots for receiving and supporting the jaws at different selected distances from the axis of the pulling ring to accommodate the device to different hub sizes. The tool permits the engagement of a hub and the application of sufficient pulling force to pull the hub from the shaft on which the hub is stuck by corrosion and the like.

2 Claims, 5 Drawing Figures PULLING TOOL This application is a continuation in part of my application Ser. No. l23,l52 filed Mar. II, 1971, now U.S. Pat. No. 3,748,718, entitled PULLING TOOL.

The invention relates to pulling tools and, more specifically relates to a pulling tool for removal of a hub from a shaft.

The great expansion of the air conditioning industry, especially in its acceptance for residential cooling, has resulted in the use of a large number of outdoor fans for condenser cooling purposes. Such fans are exposed to weather the year round and thus are very susceptible to corrosion factors. Generally, the fans used for such purposes have cylindrical sleeve-like hubs provided with smooth external surfaces which aredifflcult to engage when attempting to remove the hub from a shaft on which it is mounted. More often than not, theend results of efforts at fan removal is fan destruction, which not only substantially increases the labor costs for personnel performing the services but also necessitates substantial increase in replacement parts costs.

Accordingly, it is'a principal object of the invention to provide a new and improved pulling tool for engagement of a hub, especially a fan hub, on a shaft and removal of the hub from the shaft. i

It is another object of the invention to provide apulling tool which has a minimum of operating parts.

FIG. 5 is an exploded perspective of another, form of pulling tool embodying the principles of the invention.

In accordance with the invention there is provided a pulling tool for removing a shaft-mounted hub including an annular pulling ring having a peripheral pulling flange provided with a tapered bore, and a pair of circular segment pulling jaws having external tapered surfaces for seating against the tapered bore surface of the pulling ring and internal teeth adapted to engage the smooth surface of a fan hub. In accordance with another feature of the invention. there is provided a pulling tool for removing a hub from a shaft which includes a pulling ring having a pulling flange and provided with an axial opening defined by a plurality of pairs of circumferentially spaced slots each having a tapered seat surface at a selected distance from the axis of the ring for supporting a pair of pulling jaws. A pair of pulling jaws are provided with the pulling ring and adapted to It is another object of the invention to provide a pulle} ing tool wherein dimensional tolerances are not especially critical.

It is another object of the invention to provide a pulling tool which is readily operable with available pullers capable of engaging the shaft and pulling tool of the invention for forcing the hub from the shaft.

It is a still further object of the invention to provide a fan puller which removes a hub from a shaft with minimum damage to both the shaft and the hub.

It is still a further object of the invention to provide a pulling tool of the character described which is useful with various diameter hubs by changing only the pulling jaws of the tool.

It is another object of the invention to provide a further form of pulling tool of the character described which is useful with various diameter hubs by shifting the pulling jaws to the appropriate slots in the pulling ring whereby the same pulling ring and jaws are useful to remove a wide range of hub diameters.

A still further object of the invention is to provide a pulling tool which is readily disassembled from the pulled hub after the hub has been disengaged from a shaft.

These and further objects and advantages of the'invention will be apparent from reading the following description of a pulling tool embodying the invention in conjunction with the accompanying drawings wherein:

FIG. 1 is a side view in elevation of a typical fan hav-- ing a sleeve-like mounting hub on the shaft of an electric motor; 7

FIG. 2 is an enlarged fragmentary view in section and elevation illustrating a pulling tool embodying they invention assembled on a fan hub and engaged by a suitable pulling tool;

FIG. 3 is an exploded perspective view of a complete pulling tool embodying the invention;

FIG. 4 is a front view in elevation showingthe pulling tool assembled on a hub mounted on a shaft as seen along the line 44 of FIG. 2; and

stock which is bored and threaded along its longitudibe positioned in the various corresponding pairs of circumferentially spaced slots whereby a single pulling ring and pair of pulling jaws adapt the device to various diameter hubs depending upon the pair of slots selected for the jaws.

, Referring to FIG- 1 of the drawings, a typical fan 5 having a sleeve-like hub 6 is mounted on a shaft 7 of a motor 8. It will be obvious that the smooth outer surface of the sleeve-like hub 6 is difficult to engage with presently available tools andapply force without damage to move the sleeve hub relative to the shaft 7. A pulling tool embodying the invention-is readily engageable, as shown in FIG. 2,*with the hub of the fan for purposes of forcing the hub from the shaft.

Referring to FIG. 2, a pulling tool 10 embodying the invention is shown assembled on the fan hub 6 for removing the hub from the shaft 7. For applying a pulling force to the fan puller relative to the shaft, a suitable conventional puller 11 is illustrated engaged in a pulling relationship between the shaft and pulling tool 10.

The pulling tool 10 includes a pulling ring 12 and a pair of identical jaw segments 13. The pulling ring has a body portion 14 which has a cylindrical outer surface 15 and a tapered or conical internal surface 20. The pulling ring also includes a pulling flange 21 which preferably is formed integral with the body portion 14 and has a back pulling shoulder surface 22 which lies in a plane substantially perpendicular to the cylindrical outer side surface 15 of the pulling ring body. As obvious from FIG. 3, the pulling flange is a peripheral feature extending entirely around the pulling ring so that it is engageable at any location around the ring. The flange must be of sufficient thickness to withstand substantial pulling forces applied to it in removing a hub from a shaft. If desired, the shoulder surface 22 might be somewhat undercut or formed to slope radially inwardly toward the flange to lie at an acute angle with the surface 15 to facilitate engagement of the pulling ring surface by a puller, such as the tool 11.

Each of the jaw segments 13 has an internal longitudinally extending semi-cylindrical recess 23 defined by a tooth or ribbed surface 24'which is a segment of a cylindrical surface with teeth formed therein running transversev to the longitudinal axis of the surface to facilitate engagement with the cylindrical surface on the fan hub 6. The surface 24 may be formed of thread segments provided in the jaw segment by making the two jaw segments shown from a piece of cylindrical bar nal axis to provide the tooth surface 24. Theouter' surface of the jaw segments is a tapered or conical surface 25 generated along the same longitudinal axis as the internal tooth surface 24. The degree of slope of the surface 25 corresponds with the slope of the pulling ring internal surface 20 so that when assembled on the fan hub 6, the segments 13 will firmly seat on and engage with the pulling ring surface 20. Circumferentially each of the pulling jaws 13 extends slightly less than 180, as is evident in FIG. 4, so that even when substantial pressure is applied to the jaws, forcing them inwardly around the fan hub, there will be no contact by the inside faces 30 of the two segments which would tend to hold them apart to lessen their gripping capability against the hub.

' As particularly evidentin FIG. 2, the length of the jaw segments 13 as measured along the longitudinal axis of the segments between the front faces31 and the back faces 32 is greater than'the length of the pulling ring 12 as measured along its longitudinal axis between its front face 33and back face 34 to facilitate disassembly of thefan puller from the fan hub, as explained in greater detail hereinafter.

in the body 40 by grasping the head end 44 of the rod and'turning the rod until the foot 43 of the rod engages the free end face 42 of the fan shaft 7. During assembly of the pulling tool on the fan hub and of the puller 1 1 on the pulling tool, a reasonable degree of care is exercised to properly align the jaw segments and pulling ring on the fan hub and to align the puller 11 with the shaft and pulling ring. It will be recognized that the results of suchcare will more firmly seat the jaw segments on the fan hub and the pulling ring with the jaw segments to optimize the application of the required forces with minimum damage to the various parts of the system.

The push rod 41 is then rotated by means of a suitable tool engaged with the foot 44 applying a force toward the free end face 42 of the shaft 7 while simultaneously applying a force away from the fan blades in The puller 11 is a suitable conventional tool having 3 a body 40 .through which a threaded push rod 41 is rotatably supported for applying a force between the body and the end face 42 of the shaft 7. The push rod has a pushing foot 43 and a multi-fac eted head'end 44 engageable by a suitable tool, such as a wrench. A pair ofC-shaped pulling arms45 are pivotally supported by pins 50 from the opposite ends of the body 40. The pulling arms have hooked end portions 51 which are engageable with the back shoulder 22- of the pulling flange 21 on the pulling ring 12.

When a fan hub, such as the hub 6, requires removal from a shaft 7, the pulling ring 12 alone is placed over the shaft 7 andforward end portion 6a of the fan hub 6, with the back face 34 of the pulling ring facing the blades of the fan. The pulling ring is held manually at a position 'at which the longitudinal axis of the ring is substantially aligned with the axis of the shaft and fan hub, and thus the ring is concentric with and spaced from the fan hub 6. The pulling ring may be held at a position at which the back face 34 of the ring approximately touches the front or forward edges of the fan blades so that as much as possible of the free end of the shaft 7 extends through the pulling ring. The two jaw segments 13 are then placed on opposite sides of the fan hub 6, as shown in FIG. 4, with the inner toothed surfaces 24 ofthe jaw segments resting on the outer cylindrical surface of the fan hub. The jaw segments are moved rearwardly away from the free end of the fan shaft into the conical bore of the pulling ring until the back faces 32 of the jaw segments touch or are closely spaced from the front edges of the fan blades. Thepulling ring is then moved forwardly away from the fan blades toward the front free end of the shaft 7 until the inner tapered surfaces 20 of the jaw segments. With the pulling ring being held with a light, even force for wardly so that the jaw segments 13 are supported firmly inwardly around the fan hub 6, the puller 11 is assem' bled on the pulling tool 10 and the shaft. The push rod 41 is retracted sufficiently to permit the arms 45 to be swung into place, as shown in FIG. 2, with their hooked end portions 51 engaging the back face 22 of the peripheral pulling flange 21 on the pulling ring. With the arms held in this position, the push rod is then rotated the opposite direction. The opposite direction force is applied to the back face 22 of the pulling flange 21 on the pulling ring by the arms 45. The wedging effect of the engagement of the pulling ring'tapered surface 20 against the jaw segment tapered surfaces 25 applies a radially inwardly directed force component to the jaw segments which tightly squeezes them around the fan hub 6 against its outer cylindrical surface, while simultaneously the longitudinal component of the wedging force applied to the jaw segments parallel to the axis of the shaft and fan hub tends to force the fan hub 6 toward the free end 42 of the shaft 7. Careful, steady application of the'pushing force of the push rod 41 pulls the fan hub 6 off the shaft 7 with essentially little or no damage to either the shaft or the surface of the fan hub v 6'and with no danger of contact with the fan blades.

When so removing the fan from the shaft with the pulling tool, the force applied to the pulling ring may provide a sufficient wedging effect to the jaw segments that the fan puller may require a slight force or jaw to disengage it from the fan hub 6. The relative length of the jaw segment 13 and the pulling ring, as previously discussed, positions thebac-k face 34 of the pulling ring a substantial distance in front of the fan blades, particularly by the time sufficient force is applied to and wedges the jaw segments 13 on the fan hub to remove the fan from the shaft. The space between the back face 34 of the pulling ring and the fan blades permits the pulling ring to be lightly tapped around its flange 21 toward the fan blades, without damage to the fan blades, to release the tapered surface 20 of the pulling ring from the surfaces 25 of the jaw segments. Reasonably short movement of the pulling ring toward the fan blades allows the jaw segments 13 to be disengaged from the surface of the hub 6 and lifted forwardly from the hub and fromwithin the bore of the pulling ring. The pulling ring then is lifted from the fan hub. The substantial length of the toothed surface 24 which is engageable with the fan hub surface for pulling the hub off theshaft, permits the application of the force necessaryto free the fan hub with minimum scarring or damage to the hub surface. The only actual contact with the shaft itself during the removal process is engagement of the foot 43 of the push rod on the puller 11 with the that for any given pulling ring, several jaw segments may be used with the ring, each set having inner toothed surfaces 24 of different diameters while having the same dimensions on the outer tapered surfaces 25 so that the various sets of jaw segments permits a single pulling ring to be used with varying diameter fan hubs. It will be further recognized that the jaw segments 13 may be made in other than pairs, such as by using three instead of two segments, though such an arrangement would be appreciably more difficult to handle manually and is not considered to offer any substantial advantage over the arrangement shown and described.

Referring to FIG. 5 another form of pulling tool50 is illustrated for use with a plurality of hub diameters. The tool 50 includes a pulling ring 51 and a pair ofjaws 52. The ring 51 corresponds with the pulling ring 12 and the jaws 52 with the jaws 13 of the pulling tool illustrated in FIGS. 2 4. The pulling ring 51 has a central body portion 53 having a cylindrical outer surface portion 54. The pulling ring also includes an integral pulling flange 55 corresponding with the flange 21 on the pulling ring 12. The pulling flange 55 has a back face 60 which is perpendicular to the axis of the pulling ring and to the cylindrical body surfaces 54 so that the ring flange 55 is readily engaged by the puller 11 in exactly the same manner as illustrated in FIG. 12. The pulling ring is provided with a symmetrical central opening 61 defined by a plurality of pairs of circumferentially spaced slots which extend longitudinally through the pulling ring oriented around the axis 62 of the ring. The opening 61 is thus formed by a first pair of diametrically opposed slots 63, a second pair of diametrically opposed slots 64, a third pair of diametrically opposed slots 65, and a fourth pair of diametrically opposed slots 70. Each of the slots in the pulling ring is defined by parallel spaced apart side walls, which extend longitudinally through the pulling ring body parallel with the axis 62, and an outer wall surface which lies perpendicular to and connects the two side wall surfaces and slopes or tapers toward the axis 62 in a direction toward the back of the pulling ring away from the pulling flange 55-. For example, the slots 63 facing the viewer in FIG. 5 is defined by slot side walls 63a and an outer wall or supporting seat'surface 63b against which one of the jaws 52 rests when in the slot 63. The slopes of the seat surfaces 63b of the slot 63 correspond with the slope of the internal tapered seat surface in the pulling ring 12 so that the jaws are properly urged against the hub when removing a hub from a shaft. Each of the slots of'the other pairs of diametrically opposed slots has corresponding side walls and an outer seat wall surface to support the pulling jaws when in the respective pairs of slots. Each of the pulling jaws 52 has an inner hub gripping surface 52a having a plurality of tooth segments 52b which correspond with the teeth 24 of the pulling jaws 13. The jaws 52 have opposite end surfaces 520 whichare perpendicular to the axis 62 when the jaws are in operating position. The jaws have side parallel walls 52d and an outer tapered planar wall surface 52e. When in operating position within a slot of the pulling ring, the side walls 52d of each of the jaws engages the side walls of the slot, such, for example, as the side walls of 64a of the slot 64, and the tapered outerwall surface 52e of each jaw engages the tapered seat surface of the slot as, for example, the seat surface 64b of the slot 64. In FIG. 5, the jaws 52 are illustrated in alignment with the pulling ring slots 64, so that if the jaws were moved into pulling positions within the pulling ring, the seat surface 52e of the lower jaw would rest on the slot seat surface 64b to properly support the jaw and apply the necessary force against the hub surface when the pulling ring and jaws are urged forward by the puller 11. The radial depth of each of the pairs of the slots of the pulling ring varies so that the seat surfaces of each of the pairs of slots are at different distances from the axis 62 of the pulling ring thereby providing various radial positions for the jaws to accommmodate the tool to different hub diameters. In the particular configuration of the pulling ring illustrated in FIG. 5, the pair of slots 64 have seat surfaces 6412 located the farthest from the pulling ring axis so that when the jaws 52 are disposed in'the two slots 64 the tool is adapted to fit the largest diameter hub which can be pulled with the tool. The pair of pulling ring slots 65 supports the pulling jaws for a smaller diameter size range of hub which can be pulled with the tool. The seat surfaces of the pairs of slots and 63 are farther from the axis of the pulling ring' and thus support the jaws at other effective diameters for pulling different size hubs.

The pulling tool 50 is used by following the same procedural steps outlined in connection with the tool 10 and illustrated particularly in FIG. 2. The pulling ring 51 is placed over the hub 6 in the same position as illustrated for the pulling ring 12 in FIG. 2. The jaws 52 are placed within the pair of opposed pulling ring slots which will permit the jaws to be inserted into the slots along opposite outside surface portions of the hub 6. The pulling ring is then pulled forward on the hub so that the seat surfaces of the slots engage the outer surfaces 52e of the jaws to urge the inner tooth surfaces 52b of the pulling jaws against the hub outer surface. The puller 11 is then secured on the pulling tool and shaft as shown in FIG. 2. The hook portions of the puller are engaged with the back face 60 of the pulling flange 55 while the shaft end face 42 of the shaft 7 is engaged by the foot 43 of the push rod on the puller. In this pulling position, the pulling ring and jaws would appear in cross section essentially identical to FIG. 2. Rotating the push rod of the puller urges the pulling ring outwardly on the shaft forcing the jaws 52 against the hub toward the free end of the shaft7 to loosen the hub and pull it from the shaft, as previously described.

It will be seen that the pulling tool 10 is readily accommodated to varying hub sizes by the use of different size jaws 13 while the pulling tool 50 is readily accommodated to various hub sizes by selecting the proper pair of pulling ring slots in which to position the pulling jaws. Thus, a single pulling ring and one pair of jaws are used for a wide range of hub diameters. While the jaw surfaces 52e and the pulling ring slot seat surfaces are shown as plane surfaces, it will be recognized that such surfaces may be cylindrical surface segments if desired.

It will be seen that the fan puller embodying the invention requires only a minimum number of parts, is operable with essentially no damage to the shaft or fan hub, is providable in assorted sizes to fit various diameter'shafts with a minimum number of parts required to provide such flexibility, and is readily usable with standard pulling tools. I

What is claimed and desired to be secured by Letters Patentis:

l. A pulling tool for removing a sleeve-type hub from a shaft comprising: a pulling ring adapted to be supported concentrically over said hub in spaced relation thereto to define an opening within said ring around said hub, said pulling ring having external peripheral axis of said pulling ring in a direction away from said pulling flange; and a pair of jaw segments, each of said jaw segments having a generally cylindrical internal gripping surface adapted to engage said hub for pulling said hub from said shaft and a tapered external surface adapted to seat on one of said bottom seat surfaces of said longitudinal slots of said pulling ring whereby each of said jaw segments is wedged between said pulling ring and said hub responsive to a force applied to the back face of said flange on said pulling ring, said jaw segments being selectively positionable in each of said pairs of said slots at different distances from said axis of said pulling ring to accommodate said tool to different hub sizes, and saidjaw segments when assembled in said pulling ring occupying less than 360 of the 4 space between said hub and said pulling ring.

2. A pulling tool in accordance with claim 1 wherein the seat surface in each of said slots in said pulling ring is a plane surface and the outer surface of each of said jaw segments is a corresponding plane surface adapted to engage said plane surface of each of said slots. 

1. A pulling tool for removing a sleeve-type hub from a shaft comprising: a pulling ring adapted to be supported concentrically over said hub in spaced relation thereto to define an opening within said ring around said hub, said pulling ring having external peripheral pulling flange for engagement of said ring by a puller arm for applying a force to said pulling flange substantially parallel with a longitudinal axis of said hub; said pulling ring further having a plurality of pairs of diametrically opposed internal circumferentially spaced longitudinal slots, the bottom seat surfaces of each said pairs of slots being at a different distance from the axis of said pulling ring from all other pairs of said slots in said pulling ring, said seat surfaces sloping longitudinally along said pulling ring convergently toward the axis of said pulling ring in a direction away from said pulling flange; and a pair of jaw segments, each of said jaw segments having a generally cylindrical internal gripping surface adapted to engage said hub for pulling said hub from said shaft and a tapered external surface adapted to seat on one of said bottom seat surfaces of said longitudinal slots of said pulling ring whereby each of said jaw segmenTs is wedged between said pulling ring and said hub responsive to a force applied to the back face of said flange on said pulling ring, said jaw segments being selectively positionable in each of said pairs of said slots at different distances from said axis of said pulling ring to accommodate said tool to different hub sizes, and said jaw segments when assembled in said pulling ring occupying less than 360* of the space between said hub and said pulling ring.
 2. A pulling tool in accordance with claim 1 wherein the seat surface in each of said slots in said pulling ring is a plane surface and the outer surface of each of said jaw segments is a corresponding plane surface adapted to engage said plane surface of each of said slots. 